TABLE 5. Panthera leo limb segment masses from the different mass estimate methods. “Flesh” is the weight calculated for the segment volumes (multiplied by 1060 kg m-3) from CT segmentation. “Reconstruction” was based on the muscle and bone reconstruction, although muscle masses for the manus and pes were calculated as total tendon mass for distal muscles. Convex hull bones (“CHB”) is the convex hull range of masses and the convex hull muscles (“CHM”) is the convex hull range of masses from the muscled reconstructions. The masses for both convex hull methods were calculated from the volumes using only the mean density [893.36 kg m−3 multiplied by 1.206 (Sellers et al., 2012)]. Ratios of each of these estimates are shown in the final four columns on the right side of the table. Dig_Man = digits of the manus, Dig_Pes = digits of the pes.

Flesh

Reconstruction

CHB Mean

CHM Mean

Flesh/Recon

Recon/CHB

CHM/Recon

Flesh/CHM

Bone mass

Muscle mass

Total

Humerus

7.47

0.44

3.94

4.38

1.19

7.29

1.71

3.69

1.67

1.02

Ulna/Radius

2.39

0.16

1.40

1.56

0.86

2.25

1.53

1.81

1.44

1.07

Manus

0.55

0.18

0.29

0.47

0.42

1.18

1.12

Dig_Man

0.44

0.07

0.07

0.29

6.16

0.24

Femur

10.9

0.62

7.23

7.85

1.50

10.6

1.39

5.23

1.35

1.03

Tibia

2.35

0.53

1.13

1.66

1.28

2.54

1.41

1.30

1.53

0.92

Pes

0.75

0.41

0.27

0.68

0.73

1.10

0.93

Dig_Pes

0.30

0.13

0.13

0.29

2.31

0.45

TABLE 6. Centre of mass (COM) validation test for extant lion limb segments. “Original COM” was derived from CT scan data for each segment, “CHM COM” from the convex hull models fitted to the muscled limbs, and “Difference” is the “Original COM” minus “CHM COM”. Italicised numbers are long axis lengths from which the percentage (%) of segment lengths were calculated. Positive x, y, and z are anterior, dorsal, and medial, respectively, relative to the origin at the proximal end of the segment. Centre of mass (COM) was expressed as % of length (from the proximal end) relative to the total proximodistal length of the segment.

Original COM

CHM COM

Difference

Original % of length

CHM % of length

x

y

z

X

y

z

x

y

z

Humerus

0.0003

-0.1120

0.005226

-0.0067

-0.1223

0.011691

0.0070

0.0103

-0.0065

45.6

49.8

Ulna/Radius

-0.0023

-0.1093

0.001969

0.0016

-0.0935

0.002054

-0.0038

-0.0158

-0.0001

42.7

36.6

Femur

-0.0201

-0.0943

-0.0177

-0.0164

-0.1098

-0.0216

-0.0037

0.0154

0.0039

32.1

37.4

Tibia

-0.0219

-0.1497

-0.0004

-0.0230

-0.1607

-0.0009

0.0011

0.0111

0.0005

50.3

54.0

TABLE 7. Reconstructed and convex hull masses for various segments of the body of Panthera atrox. Bone mass was calculated from estimated bone density (1150 kg m-3) based on relative bone mass (25.7 kg - Table 4) divided by total bone volume (0.0223 m3). Muscle mass was calculated from the muscle and tendon that forms the majority of the segment (e.g., M. biceps brachii has tendons that extend to the scapula and the ulna, but these are all counted to the mass of the humeral segment as that is the majority of the muscle and tendon) (Table 1, Table 2, Table 3), with tendons for the distal muscles being placed in the manus and pes segments. Convex hull bones’ (CHB) and convex hull muscles’ (CHB) masses were calculated from the volumes multiplied by relative density (893.36 kg m−3 multiplied by 1.091, 1.206, and 1.322 (Sellers et al., 2012) respectively). Dig_Man and Dig_Pes are the digits for the manus and pes, respectively. The Recon/CHB is the ratio of reconstructed mass to CHB mass, and CHM/Recon is the ratio of the CHM mass to the reconstructed mass. Rad = radius, Dig_Man = digits of the manus, Fib = fibula, Dig_Pes = digits of the pes.

Reconstruction

Convex Hull Bones

Convex Hull Muscles

Recon/CHB

CHM/Recon

Bone Mass

Muscle Mass

Total

Mean

Lower

Upper

Mean

Lower

Upper

Humerus

1.03

7.65

8.88

2.88

2.60

3.15

10.16

9.19

11.14

3.02

1.17

Ulna/Rad

0.73

1.94

2.67

2.03

1.83

2.22

4.44

4.02

4.87

1.32

1.66

Manus

0.34

0.20

0.54

0.92

0.84

1.01

1.28

1.16

1.40

0.59

2.35

Dig_Man

0.17

0.17

0.60

0.55

0.66

0.70

0.63

0.76

0.28

4.12

Femur

1.12

13.5

14.63

2.90

2.62

3.18

17.60

15.92

19.29

5.05

1.20

Tibia/Fib

0.87

1.99

2.86

1.89

1.71

2.07

4.33

3.92

4.75

1.51

1.52

Pes

0.90

0.61

1.50

1.60

1.45

1.76

2.16

1.96

2.37

0.94

1.44

Dig_Pes

0.28

0.28

0.68

0.62

0.75

0.92

0.83

1.01

0.41

3.27

TABLE 8. Centre of mass for Panthera atrox limb segments. Positive x, y, and z are anterior, dorsal, and medial, respectively, relative to the origin at the proximal end of the segment. Centre of mass (COM) was expressed as % of length (from the proximal end) relative to the total proximodistal length of the segment.

Segment

x

y

z

COM % of length

Humerus

0.002

-0.119

0.009

0.372

Ulna

-0.002

-0.117

0.001

0.360

Manus

-0.010

-0.118

-0.001

0.622

Digits

-0.015

-0.045

-0.009

0.414

Femur

-0.012

-0.144

-0.018

0.380

Tibia

-0.017

-0.200

-0.014

0.537

Pes

-0.020

-0.114

-0.010

0.464

Digits

0.001

-0.045

-0.017

0.370

TABLE 9. Moments of inertia (relative to the centre of mass; Table 8) for the limb segments of Panthera atrox. Units are kg m2.